<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      * {
        margin: 0;
        padding: 0;
      }
      .column {
        display: flex;
        flex-direction: column;
      }
      .row {
        display: flex;
        flex-direction: row;
      }
      .box {
        background-color: pink;
        border: 1 solid black;
        width: 30vw;
        height: 30vh;
        margin: 10px;
      }
      p {
        background-color: powderblue;
        margin: 10px;
        padding: 10px;
      }
      .pSelf {
        align-self: stretch;
      }
      .center {
        justify-content: center;
        align-items: center;
      }
    </style>
  </head>
  <body>
    <div class="box row center">
      <p>段落1</p>
      <p class="pSelf">段落1</p>
      <p>段落1</p>
      <p>段落1</p>
    </div>
    <div class="box column center">
      <p>段落1</p>
      <p>段落1</p>
      <p class="pSelf">段落1</p>
      <p>段落1</p>
    </div>
  </body>
</html>
